CollapseAllHandler (Eclipse Platform API Specification)

java.lang.Object
- org.eclipse.core.commands.common.EventManager
- - org.eclipse.core.commands.AbstractHandler
  - - org.eclipse.ui.handlers.CollapseAllHandler

All Implemented Interfaces:

IHandler, IHandler2
```
public class CollapseAllHandler
extends AbstractHandler
```
Collapse a tree viewer.
It can be used in a part's createPartControl(Composite) method:
```
 IHandlerService handlerService = (IHandlerService) getSite().getService(IHandlerService.class);
 collapseHandler = new CollapseAllHandler(myViewer);
 handlerService.activateHandler(CollapseAllHandler.COMMAND_ID, collapseHandler);
 
```
The part should dispose the handler in its own dispose() method. The part can provide its own collapse all handler if desired, or if it needs to delegate to multiple tree viewers.

Note: This class can be instantiated. It should not be subclasses.
Since:

3.4

Field Summary

Fields
Modifier and Type Field Description

static String COMMAND_ID
The command id for collapse all.

Constructor Summary

Constructors
Constructor Description

CollapseAllHandler(AbstractTreeViewer viewer)
Create the handler for this tree viewer.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`dispose()`	The default implementation does nothing.
`Object`	`execute(ExecutionEvent event)`	Executes with the map of parameter values by name.

Methods inherited from class org.eclipse.core.commands.AbstractHandler
addHandlerListener, fireHandlerChanged, hasListeners, isEnabled, isHandled, removeHandlerListener, setBaseEnabled, setEnabled

Methods inherited from class org.eclipse.core.commands.common.EventManager
addListenerObject, clearListeners, getListeners, isListenerAttached, removeListenerObject

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - COMMAND_ID
```
public static final String COMMAND_ID
```
    The command id for collapse all.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - CollapseAllHandler
```
public CollapseAllHandler(AbstractTreeViewer viewer)
```
    Create the handler for this tree viewer.
    
    Parameters:
    
    viewer - The viewer to collapse. Must not be null.
- Method Detail
  - execute
```
public Object execute(ExecutionEvent event)
```
    Description copied from interface: IHandler
    
    Executes with the map of parameter values by name.
    
    Parameters:
    
    event - An event containing all the information about the current state of the application; must not be null.
    
    Returns:
    
    the result of the execution. Reserved for future use, must be null.
  - dispose
```
public void dispose()
```
    Description copied from class: AbstractHandler
    
    The default implementation does nothing. Subclasses who attach listeners to other objects are encouraged to detach them in this method.
    
    Specified by:
    
    dispose in interface IHandler
    
    Overrides:
    
    dispose in class AbstractHandler